Scientific Consensus - Uncertainty and Scientific Consensus in Policy Making

Uncertainty and Scientific Consensus in Policy Making

In public policy debates, the assertion that there exists a consensus of scientists in a particular field is often used as an argument for the validity of a theory and as support for a course of action by those who stand to gain from a policy based on that consensus. Similarly arguments for a lack of scientific consensus are often encouraged by sides who stand to gain from a more ambiguous policy.

People of various backgrounds (political, scientific, media, action groups, and so on) have argued that there is a scientific consensus on the causes of global warming. The historian of science Naomi Oreskes published an article in Science reporting that a survey of the abstracts of 928 science articles published between 1993 and 2003 showed none which disagreed explicitly with the notion of anthropogenic global warming. In an editorial published in the Washington Post, Oreskes stated that those who opposed these scientific findings are amplifying the normal range of scientific uncertainty about any facts into an appearance that there is a great scientific disagreement, or a lack of scientific consensus. Oreskes's findings were replicated by other methods that require no interpretation.

The theory of evolution through natural selection is an accepted part of the science of biology, to the extent that few observations in biology can be understood without reference to natural selection and common descent. Opponents of evolution claim that there is significant dissent on evolution within the scientific community. The wedge strategy, an ambitious plan to supplant scientific materialism seen as inimical to religion, with a religion-friendly theistic science, depended greatly on seeding and building on public perceptions of absence of consensus on evolution. Stephen Jay Gould has argued that creationists misunderstand the nature of the debate within the scientific community, which is not about "if" evolution occurred, but "how" it occurred.

The inherent uncertainty in science, where theories are never proven but can only be disproven (see falsifiability), poses a problem for politicians, policymakers, lawyers, and business professionals. Where scientific or philosophical questions can often languish in uncertainty for decades within their disciplinary settings, policymakers are faced with the problems of making sound decisions based on the currently available data, even if it is likely not a final form of the "truth". The tricky part is discerning what is close enough to "final truth". For example, social action against smoking probably came too long after science was 'pretty consensual'.

Certain domains, such as the approval of certain technologies for public consumption, can have vast and far-reaching political, economic, and human effects should things run awry of the predictions of scientists. However, insofar as there is an expectation that policy in a given field reflect knowable and pertinent data and well-accepted models of the relationships between observable phenomena, there is little good alternative for policy makers than to rely on so much of what may fairly be called 'the scientific consensus' in guiding policy design and implementation, at least in circumstances where the need for policy intervention is compelling. While science cannot supply 'absolute truth' (or even its complement 'absolute error') its utility is bound up with the capacity to guide policy in the direction of increased public good and away from public harm. Seen in this way, the demand that policy rely only on what is proven to be "scientific truth" would be a prescription for policy paralysis and amount in practice to advocacy of acceptance of all of the quantified and unquantified costs and risks associated with policy inaction.

No part of policy formation on the basis of the ostensible scientific consensus precludes persistent review either of the relevant scientific consensus or the tangible results of policy. Indeed, the same reasons that drove reliance upon the consensus drives the continued evaluation of this reliance over time—and adjusting policy as needed.